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  • 351. Berglund, Björn
    et al.
    Khan, Ghazanfar Ali
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Weisner, Stefan E.B.
    Ehde, Per Magnus
    Fick, Jerker
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Lindgren, Per-Eric
    Exposure of constructed wetlands to environmental concentrations of antibiotics show no effect on antibiotic resistance gene selection and expressionManuscript (preprint) (Other academic)
  • 352. Berglund, Linn
    et al.
    Anugwom, Ikenna
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Laboratory of Industrial Chemistry and Reaction Engineering, Johan Gadolin Process Chemistry Centre, Åbo Akademi University, Turku, Finland.
    Hedenström, Mattias
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Aitomäki, Yvonne
    Mikkola, Jyri-Pekka
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Laboratory of Industrial Chemistry and Reaction Engineering, Johan Gadolin Process Chemistry Centre, Åbo Akademi University, Turku, Finland.
    Oksman, Kristiina
    Switchable ionic liquids enable efficient nanofibrillation of wood pulp2017In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 24, no 8, p. 3265-3279Article in journal (Refereed)
    Abstract [en]

    Use of switchable ionic liquid (SIL) pulp offers an efficient and greener technology to produce nanofibers via ultrafine grinding. In this study, we demonstrate that SIL pulp opens up a mechanically efficient route to the nanofibrillation of wood pulp, thus providing both a low cost and chemically benign route to the production of cellulose nanofibers. The degree of fibrillation during the process was evaluated by viscosity and optical microscopy of SIL treated, bleached SIL treated and a reference pulp. Furthermore, films were prepared from the fibrillated material for characterization and tensile testing. It was observed that substantially improved mechanical properties were attained as a result of the grinding process, thus signifying nanofibrillation. Both SIL treated and bleached SIL treated pulps were fibrillated into nanofibers with fiber diameters below 15 nm thus forming networks of hydrophilic nature with an intact crystalline structure. Notably, it was found that the SIL pulp could be fibrillated more efficiently than traditional pulp since nanofibers could be produced with more than 30% less energy when compared to the reference pulp. Additionally, bleaching reduced the energy demand by further 16%. The study demonstrated that this switchable ionic liquid treatment has considerable potential in the commercial production of nanofibers due to the increased efficiency in fibrillation.

  • 353.
    Bergman, Denice
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Drogtester i urin: Enkätundersökning bland personal från LARO-mottagningar i Sverige2014Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 354. Bergman, Inger
    et al.
    Bishop, Kevin
    Tu, Qiang
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Frech, Wolfgang
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Åkerblom, Staffan
    Nilsson, Mats
    The influence of sulphate deposition on the seasonal variation of peat pore water methyl Hg in a boreal mire2012In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, no 9, p. e45547-Article in journal (Refereed)
    Abstract [en]

    In this paper we investigate the hypothesis that long-term sulphate (SO42-) deposition has made peatlands a larger source of methyl mercury (MeHg) to remote boreal lakes. This was done on experimental plots at a boreal, low sedge mire where the effect of long-term addition of SO42- on peat pore water MeHg concentrations was observed weekly throughout the snow-free portion of 1999. The additions of SO42- started in 1995. The seasonal mean of the pore water MeHg concentrations on the plots with 17 kg ha(-1) yr(-1) of sulphur (S) addition (1.3 +/- 0.08 ng L-1, SE; n=44) was significantly (p<0.0001) higher than the mean MeHg concentration on the plots with 3 kg ha(-1) yr(-1) of ambient S deposition (0.6 +/- 0.02 ng L-1, SE; n=44). The temporal variation in pore water MeHg concentrations during the snow free season was larger in the S-addition plots, with an amplitude of >2 ng L-1 compared to +/-0.5 ng L-1 in the ambient S deposition plots. The concentrations of pore water MeHg in the S-addition plots were positively correlated (r(2)=0.21; p=0.001) to the groundwater level, with the lowest concentrations of MeHg during the period with the lowest groundwater levels. The pore water MeHg concentrations were not correlated to total Hg, DOC concentration or pH. The results from this study indicate that the persistently higher pore water concentrations of MeHg in the S-addition plots are caused by the long-term additions of SO42- to the mire surface. Since these waters are an important source of runoff, the results support the hypothesis that SO42- deposition has increased the contribution of peatlands to MeHg in downstream aquatic systems. This would mean that the increased deposition of SO42- in acid rain has contributed to the modern increase in the MeHg burdens of remote lakes hydrologically connected to peatlands.

  • 355.
    Bergman, Maud
    Umeå University, Faculty of Medicine, Department of Odontology. Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Chemical and thermodynamic studies of dental gold alloys with special reference to homogenization, electrochemical corrosion and cluster formation1976Doctoral thesis, comprehensive summary (Other academic)
  • 356.
    Bergman, Nina
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Downs syndrom: Läkemedelsbehandling vid Alzheimers sjukdom och vid kognitiv funktionsnedsättning hos yngre och vuxna med Downs syndrom2012Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
  • 357. Bergmann, Rikke
    et al.
    Linusson, Anna
    Umeå University, Faculty of Science and Technology, Chemistry.
    Zamora, Ismael
    SHOP: Scaffold HOPping by GRID-Based Similarity Searches2007In: Journal of Medicinal Chemistry, Vol. 50, no 11, p. 2708-2717Article in journal (Refereed)
    Abstract [en]

    A new GRID-based method for scaffold hopping (SHOP) is presented. In a fully automatic manner, scaffolds were identified in a database based on three types of 3D-descriptors. SHOP's ability to recover scaffolds was assessed and validated by searching a database spiked with fragments of known ligands of three different protein targets relevant for drug discovery using a rational approach based on statistical experimental design. Five out of eight and seven out of eight thrombin scaffolds and all seven HIV protease scaffolds were recovered within the top 10 and 31 out of 31 neuraminidase scaffolds were in the 31 top-ranked scaffolds. SHOP also identified new scaffolds with substantially different chemotypes from the queries. Docking analysis indicated that the new scaffolds would have similar binding modes to those of the respective query scaffolds observed in X-ray structures. The databases contained scaffolds from published combinatorial libraries to ensure that identified scaffolds could be feasibly synthesized.

  • 358.
    Bergqvist, Ewa
    et al.
    Umeå University, Faculty of Science and Technology, Department of Science and Mathematics Education. Umeå University, Faculty of Science and Technology, Umeå Mathematics Education Research Centre (UMERC). Umeå University, Faculty of Science and Technology, Department of Mathematics and Mathematical Statistics.
    Bergqvist, Tomas
    Umeå University, Faculty of Science and Technology, Department of Science and Mathematics Education. Umeå University, Faculty of Science and Technology, Umeå Mathematics Education Research Centre (UMERC). Umeå University, Faculty of Social Sciences, Department of applied educational science.
    Vingsle, Lotta
    Umeå University, Faculty of Science and Technology, Department of Science and Mathematics Education. Umeå University, Faculty of Science and Technology, Umeå Mathematics Education Research Centre (UMERC).
    Wikström Hultdin, Ulrika
    Umeå University, Faculty of Science and Technology, Department of Science and Mathematics Education. Umeå University, Faculty of Science and Technology, Umeå Mathematics Education Research Centre (UMERC). Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Österholm, Magnus
    Umeå University, Faculty of Science and Technology, Department of Science and Mathematics Education. Umeå University, Faculty of Science and Technology, Umeå Mathematics Education Research Centre (UMERC).
    How mathematical symbols and natural language are integrated in textbooks2020Conference paper (Other academic)
    Abstract [en]

    In mathematical text and talk, natural language is a constant companion to mathematical symbols. The purpose of this study is to identify different types of relations between natural language and symbolic language in mathematics textbooks. Here we focus on the level of integration. We have identified examples of high integration (e.g., when symbols are part of a sentence), medium integration (e.g., when the shifts between natural and symbolic language occurs when switching to a new line), and low integration (e.g., when symbols and written words are connected by the layout).

  • 359.
    Bergqvist, Ewa
    et al.
    Umeå University, Faculty of Science and Technology, Department of Science and Mathematics Education. Umeå University, Faculty of Science and Technology, Umeå Mathematics Education Research Centre (UMERC). Umeå University, Faculty of Science and Technology, Department of Mathematics and Mathematical Statistics.
    Bergqvist, Tomas
    Umeå University, Faculty of Science and Technology, Department of Science and Mathematics Education. Umeå University, Faculty of Science and Technology, Umeå Mathematics Education Research Centre (UMERC). Umeå University, Faculty of Social Sciences, Department of applied educational science.
    Vingsle, Lotta
    Umeå University, Faculty of Science and Technology, Department of Science and Mathematics Education. Umeå University, Faculty of Science and Technology, Umeå Mathematics Education Research Centre (UMERC).
    Wikström Hultdin, Ulrika
    Umeå University, Faculty of Science and Technology, Department of Science and Mathematics Education. Umeå University, Faculty of Science and Technology, Umeå Mathematics Education Research Centre (UMERC). Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Österholm, Magnus
    Umeå University, Faculty of Science and Technology, Department of Science and Mathematics Education. Umeå University, Faculty of Science and Technology, Umeå Mathematics Education Research Centre (UMERC).
    How mathematical symbols and natural language are used in teachers’ presentations2020Conference paper (Other academic)
    Abstract [en]

    In this study, we examine how the use of natural language varies, considering the symbolic language in procedural and conceptual aspects of mathematics.

  • 360.
    Bergqvist, Joakim
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Forsman, Oscar
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Larsson, Pär
    Umeå University, Faculty of Medicine, Department of Medical Biosciences.
    Näslund, Jonas
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Lilja, Tobias
    Engdahl, Cecilia
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Lindström, Anders
    Gylfe, Åsa
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Ahlm, Clas
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Evander, Magnus
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology. Umeå University, Arctic Research Centre at Umeå University.
    Bucht, Göran
    [ 1 ] CBRN Def & Secur, Swedish Def Res Agcy, SE-90182 Umea, Sweden.
    Detection and Isolation of Sindbis Virus from Mosquitoes Captured During an Outbreak in Sweden, 20132015In: Vector Borne and Zoonotic Diseases, ISSN 1530-3667, E-ISSN 1557-7759, Vol. 15, no 2, p. 133-140Article in journal (Refereed)
    Abstract [en]

    Mosquito-borne alphaviruses have the potential to cause large outbreaks throughout the world. Here we investigated the causative agent of an unexpected Sindbis virus (SINV) outbreak during August-September, 2013, in a previously nonendemic region of Sweden. Mosquitoes were collected using carbon dioxide-baited CDC traps at locations close to human cases. The mosquitoes were initially screened as large pools by SINV-specific quantitative RT-PCR, and the SINV-positive mosquitoes were species determined by single-nucleotide polymorphism (SNP) analysis, followed by sequencing the barcoding region of the cytochrome oxidase I gene. The proportion of the collected mosquitoes was determined by a metabarcoding strategy. By using novel strategies for PCR screening and genetic typing, a new SINV strain, Lovanger, was isolated from a pool of 1600 mosquitoes composed of Culex, Culiseta, and Aedes mosquitoes as determined by metabarcoding. The SINV-positive mosquito Culiseta morsitans was identified by SNP analysis and sequencing. After whole-genome sequencing and phylogenetic analysis, the SINV Lovanger isolate was shown to be most closely similar to recent Finnish SINV isolates. In conclusion, within a few weeks, we were able to detect and isolate a novel SINV strain and identify the mosquito vector during a sudden SINV outbreak.

  • 361.
    Bergqvist, Per-Anders
    et al.
    Umeå University, Faculty of Science and Technology, Chemistry.
    Augulyte, Lijana
    Umeå University, Faculty of Science and Technology, Chemistry.
    Jurjoniene, Violeta
    PAH and PCB removal efficiencies in Umeå (Sweden) and Šiauliai (Lithuania) municipal wastewater treatment plants2006In: Water, Air and Soil Pollution, ISSN 0049-6979, Vol. 175, no 1-4, p. 291-303Article in journal (Refereed)
    Abstract [en]

    Dissolved concentrations of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in the influents and effluents of two municipal sewage treatment plants (STPs) were monitored over 16- (Umeå, Sweden) and 22- (Šiauliai, Lithuania) day sampling periods. Sampling was performed using a passive sampling technique (semipermeable membrane devices; SPMDs) for sequestration of the dissolved (readily bioavailable) fraction of persistent organic pollutants (POPs). Removal efficiencies for individual low molecular weight (LMW) PAH compounds varied from 84% to levels at which the compounds were not detected in effluents from Umeå. The corresponding efficiencies of the Šiauliai plant were 33–95%. Measurements revealed that dissolved concentrations of most of the PCBs and some of the high molecular weight (HMW) PAHs increased during the conventional wastewater treatment at both plants. The release of dissolved PAHs and PCBs in the effluents from municipal wastewater treatment plants might increase the environmental contamination by readily bioavailable pollutants in the recipient waters; the rivers Umeälven and Kulpè. SPMDs were found to be suitable sampling tools for long-term (weeks-month) integrative monitoring of trace concentrations of the dissolved fraction of hydrophobic pollutants in the wastewater process, since the sampling and clean-up steps were easy to perform.

  • 362.
    Bergqvist, Per-Anders
    et al.
    Umeå University, Faculty of Science and Technology, Chemistry.
    Jegorova, Ilona
    Kaunelienė, Violeta
    Žaliauskienė, Audronė
    Dissolved Organochlorine and PAH Pollution Profiles in Lithuanian and Swedish Surface Waters2007In: Bulletin of Environmental Contamination and Toxicology, Vol. 79, no 2, p. 147-52Article in journal (Refereed)
    Abstract [en]

    In recent decades, knowledge and concern regarding persistent organic pollutants and the environmental hazards they may pose have increased considerably, leading to international agreements such as the United Nations environment program Stockholm convention on persistent organic pollutants (POPs), to minimize further release of POPs into the environment (UNECE Protocol, 1979; UNEP Stockholm convention, 2001; UNECE Convention, 1998). National POP monitoring programs should be designed to identify, characterize and address the release of the POPs listed in the Stockholm convention. However, analyses of grab samples only provide crude snapshots of total concentrations at single points in space and time, which may be highly unrepresentative of average concentrations, and fail to account for differences in the POPs’ bioavailability and various other relevant factors. To obtain a better understanding of the fate and availability of pollutants in the environment it is necessary to obtain data regarding their site-specific and regional exposure levels. Exposure levels expressed in terms of total chemical concentrations do not reflect the actual exposure of organisms, and thus may not accurately reflect the true risks posed. Therefore, environmental monitoring programs would be improved by using reliable, integrative sampling methods that would not only allow time-weighted average concentrations of pollutants in the environment to be determined, but also facilitate assessments of the risks these chemicals pose to the environment.

  • 363.
    Bergqvist, Per-Anders
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Kauneliene, Violeta
    Cicenaite, Aurelija
    Jegorova, Ilona
    Katkeviciute, Jolita
    Tentative levels of pops in Lithuanian environment2005In: Environment, technology, resources: proceedings of the 5th International Scientific and Practical Conference on Environment, Technology and Resources, JUN 16-18, 2005 / [ed] Noviks, G, Rezekne: Rezekne higher education institution - Rezeknes Augstskola , 2005, p. 172-178Conference paper (Refereed)
    Abstract [en]

    Persistent Organic Pollutants (POPs) are chemical substances that persist in the environment, bioaccumulate through the food web, and pose a risk of causing adverse effects to human health and the environment. The Stockholm Convention is a global treaty to protect human health and the environment from POPs. In implementing the Convention, Governments will take measures to eliminate or reduce the release of POPs into the environment. This study was done in order to evaluate tentative POPs levels in Lithuania. Limited amount of PAHs and PCBs were analyzed in Siauliai air, in two biggest Lithuanian rivers - Nemunas and Neris, and in one of the biggest waste landfill in Lapes. Sampling was done using semipermeable membrane devices (SPMDs). The same procedure of sampling and analyses was used to ensure data comparability. In general, POPs pollution levels were compared with results from other studies.

  • 364.
    Bergqvist, Per-Anders
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Zaliauskiene, Audrone
    Field study considerations in the use of passive sampling devices in water monitoring2007In: Passive Sampling Techniques in Environmental Monitoring / [ed] R. Greenwood, G. Mills and B. Vrana, Amsterdam: Elsevier, 2007, p. 311-328Chapter in book (Other academic)
    Abstract [en]

    Semipermeable membrane devices (SPMDs) are passive monitors that are being increasingly used by monitoring agencies and wastewater dischargers to measure the contents of lipophilic organic chemicals that may adversely affect water quality. This chapter addresses the most frequently asked questions regarding the use of SPMDs for water monitoring and other questions related to the field application of SPMDs. It provides a sound understanding of the applicability and limitations of SPMDs for obtaining reliable monitoring data. The chapter discusses under field study considerations: pre-exposure considerations; SPMD storage considerations; and precautions/procedures during deployment and retrieval of SPMDs. In environmental monitoring projects using SPMDs, quality control (QC) procedures for sampling and analysis are applied to ensure that the data are of high quality. Appropriate QC samples are prepared to quantify possible sampler contamination during transport, deployment, retrieval, storage, processing, enrichment, fractionation operations and analyte recovery. In general, two groups of quality assurance measures are implemented: replicate QC and sampling device control.

  • 365.
    Bergström, Fredrik
    et al.
    Umeå University, Faculty of Science and Technology, Chemistry.
    Mikhalyov, Ilya
    Umeå University, Faculty of Science and Technology, Chemistry.
    Hägglöf, Peter
    Faculty of Medicine, Medical Biochemistry and Biophsyics.
    Wortmann, Rüdiger
    Ny, Tor
    Faculty of Medicine, Medical Biochemistry and Biophsyics.
    Johansson, Lennart B-Å
    Dimers of Dipyrrometheneboron Difluoride (BODIPY) with Light Spectroscopic Applications in Chemistry and Biology2002In: Journal of the American Chemical Society, Vol. 124, no 2, p. 196-204Article in journal (Refereed)
    Abstract [en]

    A ground-state dimer (denoted DI) exhibiting a strong absorption maximum at 477 nm ( = 97 000 M-1cm-1) can form between adjacent BODIPY groups attached to mutant forms of the protein, plasminogen activator inhibitor type 1 (PAI-1). No fluorescence from excited DI was detected. A locally high concentration of BODIPY groups was also achieved by doping lipid phases (micelles, vesicles) with BODIPY-labeled lipids. In addition to an absorption band located at about 480 nm, a new weak absorption band is also observed at ca. 570 nm. Both bands are ascribed to the formation of BODIPY dimers of different conformation (DI and DII). Contrary to DI in PAI-1, the DII aggregates absorbing at 570 nm are emitting light observed as a broad band centered at about 630 nm. The integrated absorption band of DI is about twice that of the monomer, which is compatible with exciton coupling within a dimer. The Förster radius of electronic energy transfer between a BODIPY excited monomer and the ground-state dimer (DI) is 57 ± 2 Å. A simple model of exciton coupling suggests that in DI two BODIPY groups are stacked on top of each other in a sandwich-like configuration with parallel electronic transition dipoles. For DII the model suggests that the S0 S1 transition dipoles are collinear. An explanation for the previously reported (J. Am. Chem. Soc. 1994, 116, 7801) exceptional light spectroscopic properties of BODIPY is also presented. These are ascribed to the extraordinary electric properties of the BODIPY chromophore. First, changes of the permanent electric dipole moment ( -0.05 D) and polarizability (-26 × 10-40 C m2 V-1) between the ground and the first excited states are small. Second, the S0 S1 electronic transition dipole moments are perpendicular to .

  • 366.
    Bergström, Johanna
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Identifiering av aktiva substanser: Med NIR och hyperspektralbildanalys med kemometri2013Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 367.
    Bergström, Sofie
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Kokristaller som ett sätt att öka biotillgängligheten: En litteraturstudie2013Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 368.
    Bergvall, Niklas
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Optimizing the cost efficiency for internal sizing of kraftliner paper grades2013Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
  • 369.
    Bernardini, A.
    et al.
    Padova, Italy.
    Gemo, N.
    Turku/Åbo, Finland; .
    Biasi, Paolo
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Canu, P.
    Padova, Italy.
    Mikkola, Jyri-Pekka
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Salmi, T.
    Turku/Åbo, Finland; .
    Lanza, R.
    Stockholm, Sweden.
    Direct synthesis of H2O2 over Pd supported on rare earths promoted zirconia2015In: Catalysis Today, ISSN 0920-5861, E-ISSN 1873-4308, Vol. 256, no 2, p. 294-301Article in journal (Refereed)
    Abstract [en]

    In this work Pd (0.3 or 0.6 wt.%) was supported on both ZrxM1-xO2 (M = La, Y, Ce) and on mechanical mixtures of CeO2 and ZrO2. The synthesized catalysts were characterized by XRD, TPR, AAS and CO chemisorption and tested for the direct synthesis of hydrogen peroxide in a high pressure semibatch apparatus. The reactants conversion was limited in order to avoid mass-transfer limitations. No selectivity enhancers of any kind were used and the all the materials were halide free. Small metal particles were obtained (1-2.6 nm). Supports with smaller pore diameters leaded to larger Pd particles, which in turn were found to preferentially support the formation of the peroxide. Moreover, supports with higher reducibility favored the production of H2O2, probably due to an easier reduction of the active metal, essential to achieve high selectivity. Notwithstanding the absence of enhancers, the specific activity and selectivity recorded were very high. (C) 2015 Elsevier B.V. All rights reserved.

  • 370. Bernas, Andreas
    et al.
    Salmi, Tapio
    Murzin, Dmitry Yu
    Mikkola, Jyri-Pekka
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Rintola, Mikko
    Catalytic transformation of abietic acid to hydrocarbons2012In: Topics in catalysis, ISSN 1022-5528, E-ISSN 1572-9028, Vol. 55, no 7-10, p. 673-679Article in journal (Refereed)
    Abstract [en]

    Catalytic and thermal conversion of abietic acid was investigated in a laboratory scale high-pressure autoclave. Fractionation of crude tall oil produces rosin acids of which abietic acid is the main compound. Tall oil rosin acid, a forest product industry residue, is an abundant, inexpensive and chemically desirable feedstock for production of lighter hydrocarbons that can be used as diesel fuel additives. The carboxylic acid functionality of the main reactant, abietic acid, must first be removed, followed by double bond hydrogenation of the remaining aromatic rings. In this study, a number of catalytic and non-catalytic reaction steps in the conversion of abietic acid were investigated. The aim was to study hydrogenation and decarboxylation reactions of abietic acid in order to produce lighter hydrocarbons. The experiments were performed by using toluene as a solvent as well as with neat abietic acid, in the absence of any solvent. Hydrogenation of abietic acid to tetrahydroabietic acid in toluene was successfully performed over palladium on carbon catalyst at the temperature range of 100-200 A degrees C and at 30 bar hydrogen pressure. Thermal non-catalytic decarboxylation of abietic acid in toluene takes place at 200-300 A degrees C resulting in one main product. The hydrocarbon products were further hydrogenated under hydrogen pressure. Catalytic decarboxylation of abietic acid in toluene was achieved over 5 wt% Ru/C, giving a wider product distribution than thermal decarboxylation.

  • 371. Berthelot, Claire C
    et al.
    Kamita, Shizuo George
    Sacchi, Romina
    Yang, Jun
    Nording, Malin L
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Department of Entomology, University of California Davis, Davis, CA, United States Of America.
    Georgi, Katrin
    Karbowski, Christine Hegedus
    German, J Bruce
    Weiss, Robert H
    Hogg, Ronald J
    Hammock, Bruce D
    Zivkovic, Angela M
    Changes in PTGS1 and ALOX12 Gene Expression in Peripheral Blood Mononuclear Cells Are Associated with Changes in Arachidonic Acid, Oxylipins, and Oxylipin/Fatty Acid Ratios in Response to Omega-3 Fatty Acid Supplementation2015In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 10, no 12, article id e0144996Article in journal (Refereed)
    Abstract [en]

    Introduction: There is a high degree of inter-individual variability among people in response to intervention with omega-3 fatty acids (FA), which may partly explain conflicting results on the effectiveness of omega-3 FA for the treatment and prevention of chronic inflammatory diseases. In this study we sought to evaluate whether part of this inter-individual variability in response is related to the regulation of key oxylipin metabolic genes in circulating peripheral blood mononuclear cells (PBMCs). Methods: Plasma FA and oxylipin profiles from 12 healthy individuals were compared to PBMC gene expression profiles following six weeks of supplementation with fish oil, which delivered 1.9 g/d eicosapentaenoic acid (EPA) and 1.5 g/d docosahexaenoic acid (DHA). Fold changes in gene expression were measured by a quantitative polymerase chain reaction (qPCR). Results: Healthy individuals supplemented with omega-3 FA had differential responses in prostaglandin-endoperoxide synthase 1 (PTGS1), prostaglandin-endoperoxide synthase 2 (PTGS2), arachidonate 12-lipoxygenase (ALOX12), and interleukin 8 (IL-8) gene expression in isolated PBMCs. In those individuals for whom plasma arachidonic acid (ARA) in the phosphatidylethanolamine (PE) lipid class decreased in response to omega-3 intervention, there was a corresponding decrease in gene expression for PTGS1 and ALOX12. Several oxylipin product/FA precursor ratios (e.g. prostaglandin E-2 (PGE(2))/ARA for PTGS1 and 12-hydroxyeicosatetraenoic acid (12-HETE)/ARA for ALOX12) were also associated with fold change in gene expression, suggesting an association between enzyme activity and gene expression. The fold-change in PTGS1 gene expression was highly positively correlated with ALOX12 gene expression but not with PTGS2, whereas IL-8 and PTGS2 were positively correlated. Conclusions: The regulation of important oxylipin metabolic genes in PBMCs varied with the extent of change in ARA concentrations in the case of PTGS1 and ALOX12 regulation. PBMC gene expression changes in response to omega-3 supplementation varied among healthy individuals, and were associated with changes in plasma FA and oxylipin composition to different degrees in different individuals.

  • 372. Bhattacharjee, Snehasish
    et al.
    Chakraborty, Sandipan
    Chorell, Erik
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Sengupta, Pradeep K.
    Bhowmik, Sudipta
    Importance of the hydroxyl substituents in the B-ring of plant flavonols on their preferential binding interactions with VEGF G-quadruplex DNA: Multi-spectroscopic and molecular modeling studies2018In: International Journal of Biological Macromolecules, ISSN 0141-8130, E-ISSN 1879-0003, Vol. 118, p. 629-639Article in journal (Refereed)
    Abstract [en]

    G-quadruplex (G4) structures are known to be promising anticancer drug targets and flavonols (an important class of fiavonoids) are small molecules reported to possess several health-promoting properties including those of anticancer activities. In this work, we explored the interactions of the structurally related plant flavonols kaempferol (KAE; 3,5,7,4'-OH flavone) and morin (MOR; 3,5,7,2',4'-OH flavone) with various G4-DNA sequences along with duplex DNA using a combination of spectroscopic and molecular docking studies. Our results revealed that KAE shows preferential interaction with VEGF G4-DNA in comparison to the other G4 sequences and duplex DNA. Moreover, KAE enhances the thermal stability of VEGF G4-DNA. In contrast, MOR exhibits an appreciably weaker level of interaction with both duplex and various G4-DNAs, with no significant structural specificity. The contrasting DNA binding behaviors suggest a crucial role of the 2'-OH substituent in the Bring of flavonol moiety. While KAE is relatively planar, MOR adopts a significantly non-planar conformation attributable to steric hindrance from the additional 2'-OH substituent. This small structural difference is apparently very important for the ability of KAE and MOR to interact with VEGF G4-DNA. Thus, KAE (but not MOR) appears to be an effective ligand for VEGF G4-DNA, opening up possibilities of its application for regulation of gene expression in cancer cells. 

  • 373.
    Biasi, P.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Åbo Akad Univ, Dept Chem Engn, Lab Ind Chem & React Engn, Johan Gadolin Proc Chem Ctr PCC, Biskopsgatan 8, FI-20500 Turku, Finland.
    Mikkola, Jyri-Pekka
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Åbo Akad Univ, Dept Chem Engn, Lab Ind Chem & React Engn, Johan Gadolin Proc Chem Ctr PCC, Biskopsgatan 8, FI-20500 Turku, Finland.
    Sterchele, S.
    Salmi, T.
    Gemo, N.
    Shchukarev, Andrey
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Centomo, P.
    Zecca, M.
    Canu, P.
    Rautio, A. -R
    Kordàs, K.
    Revealing the role of bromide in the H2O2 direct synthesis with the catalyst wet pretreatment method (CWPM)2017In: AIChE Journal, ISSN 0001-1541, E-ISSN 1547-5905, Vol. 63, no 1, p. 32-42Article in journal (Refereed)
    Abstract [en]

    A tailor-made Pd0/K2621 catalyst was subjected to post synthesis modification via a wet treatment procedure. The aimwas the understanding of the role of promoters and how—if any—improvements could be qualitatively related to the cat-alyst performance for the H2O2direct synthesis. The Catalyst Wet Pretreatment Method was applied in different metha-nolic solutions containing H2O2, NaBr, and H3PO4, either as single modifiers or as a mixture. The catalyst wascharacterized by Transmission Electron Microscopy and X-ray Photoelectron Spectroscopy. It was concluded that themodified catalysts give rise to higher selectivities compared to the pristi ne reference catalyst thus opening a possibilityto exclude the addit ion of the undesirable selectivity enhancers in the reaction medium. This work provides original evi-dence on the role of promoter s, especially bromide, allowing the formulation of a new reaction mechanism for one ofthe most challenging reactions recognized by the world.

  • 374. Biasi, Pierdomenico
    et al.
    Serna, Juan Garcia
    Salmi, Tapio O.
    Mikkola, Jyri-Pekka
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Department of Chemical Engineering, Process Chemistry Centre (PCC), Laboratory of Industrial Chemistry and Reaction Engineering, Åbo Akademi University, ÅBO-TURKU, Finland.
    Hydrogen Peroxide Direct Synthesis: Enhancement of Selectivity and Production with non-Conventional Methods2013In: ICHEAP-11: 11TH INTERNATIONAL CONFERENCE ON CHEMICAL AND PROCESS ENGINEERING, PTS 1-4 / [ed] Pierucci, S, Klemes, JJ, AIDIC - associazione italiana di ingegneria chimica, 2013, p. 673-678Conference paper (Refereed)
    Abstract [en]

    The present work is part of a comprehensive study on the direct synthesis of hydrogen peroxide in different fields, from chemistry to chemical engineering. Working on the different fields of the direct synthesis gave the possibility to look at the results and the challenges from different viewpoints. Here was investigated one parameter that enhances the direct synthesis. The H-2/Pd ratio is the key parameter that has to be investigated and optimize to enhance the hydrogen peroxide direct synthesis. Two reactors were built to study deeply the H-2/Pd ratio and to demonstrate how this parameter can affect the direct synthesis both in batch and continuous reactor with non-conventional experiments/methods. 1) A batch reactor was utilized as a "starving reactor" to enhance the productivity of hydrogen peroxide and to try to keep constant the selectivity. The starving method consists in refilling the hydrogen when it is consumed in the reactor. 2) A trickle bed reactor was utilized with a gradient of catalyst along the reactor to maximize both production and selectivity of hydrogen peroxide. The distribution of the catalyst along the bed gave the possibility to significantly improve the selectivity and the production of hydrogen peroxide (up to 0.5% in selected conditions). Higher production rate and selectivity were found when the catalyst concentration decreases along the bed from the top to the bottom compared to the uniformly dispersed catalyst. Selectivity in the batch reactor was enhanced by 5% and in the continuous reactor of 10%. The non-conventional experimental methods have been found to be novelty concepts to enhance the hydrogen peroxide direct synthesis.

  • 375.
    Biasi, Pierdomenico
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Industrial Chemistry and Reaction Engineering, Process Chemistry Center (PCC), Department of Chemical Engineering, Åbo Akademi University,Turku/Åbo, Finland.
    Sterchele, Stefano
    Bizzotto, Francesco
    Manzoli, Maela
    Lindholm, Sten
    Ek, Paul
    Bobacka, Johan
    Mikkola, Jyri-Pekka
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Industrial Chemistry and Reaction Engineering, Process Chemistry Center (PCC), Department of Chemical Engineering, Åbo Akademi University,Turku/Åbo, Finland.
    Salmi, Tapio
    Application of the Catalyst Wet Pretreatment Method (CWPM) for catalytic direct synthesis of H2O22015In: Catalysis Today, ISSN 0920-5861, E-ISSN 1873-4308, Vol. 246, no Special Issue, p. 207-215Article in journal (Refereed)
    Abstract [en]

    This work concerns a new technique to post-modify the catalytic material intended for use in H2O2 direct synthesis. The catalyst chosen was a commercially available 1 wt.% Pd/C. The catalyst was modified with the so-called Catalyst Wet Pretreatment Method (CWPM) that is used to post-modify prepared catalysts with aqueous solutions of NaBr, in different concentrations. The performance of pristine and the pretreated materials were then compared in the H2O2 direct synthesis and characterized before and after the catalytic tests in order to understand the role of the different concentrations of bromide in the CWPM procedure. The surface features of the different catalysts were analyzed with CO chemisorption (metal dispersion and mean particle size), Transmission Electron Microscopy (TEM, for Pd morphology and Pd particle size distributions), Inductive Coupled Plasma (ICP, for Pd content) and Ion Chromatography (IC, for bromide content). Various features of the materials prepared with the CWPM were correlated with the catalytic performance. It was found that the bromide has an active role in the reconstruction of metal phase and it does not only act as a poison for the most active catalytic sites as often reported in literature. By using this new protocol, the production H2O2 was almost doubled compared to the non-modified material when no direct promoters were added to the reaction environment.

  • 376. Bidleman, T F
    et al.
    Leone, A D
    Harner, T
    Jantunen, L M
    Alegria, H
    Falconer, R F
    Wiberg, Karin
    Umeå University, Faculty of Science and Technology, Chemistry.
    Organochlorine pesticides in the atmosphere: current usage or ghost of the past?2000Conference paper (Refereed)
  • 377.
    Bidleman, Terry
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Agosta, Kathleen
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Andersson, Agneta
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Brorström-Lundén, Eva
    Haglund, Peter
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Hansson, Katarina
    Laudon, Hjalmar
    Newton, Seth
    Nygren, Olle
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Ripszam, Matyas
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Tysklind, Mats
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Wiberg, Karin
    Atmospheric pathways of chlorinated pesticides and natural bromoanisoles in the northern Baltic Sea and its catchment2015In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. Suppl 3, no 44, p. 472-483Article in journal (Refereed)
    Abstract [en]

    Long-range atmospheric transport is a major pathway for delivering persistent organic pollutants to the oceans. Atmospheric deposition and volatilization of chlorinated pesticides and algae-produced bromoanisoles (BAs) were estimated for Bothnian Bay, northern Baltic Sea, based on air and water concentrations measured in 2011-2012. Pesticide fluxes were estimated using monthly air and water temperatures and assuming 4 months ice cover when no exchange occurs. Fluxes were predicted to increase by about 50 % under a 2069-2099 prediction scenario of higher temperatures and no ice. Total atmospheric loadings to Bothnian Bay and its catchment were derived from air-sea gas exchange and "bulk'' (precipitation ? dry particle) deposition, resulting in net gains of 53 and 46 kg year(-1) for endosulfans and hexachlorocyclohexanes, respectively, and net loss of 10 kg year(-1) for chlordanes. Volatilization of BAs releases bromine to the atmosphere and may limit their residence time in Bothnian Bay. This initial study provides baseline information for future investigations of climate change on biogeochemical cycles in the northern Baltic Sea and its catchment.

  • 378.
    Bidleman, Terry
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Andersson, Agneta
    Umeå University, Faculty of Science and Technology, Umeå Marine Sciences Centre (UMF). Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Jantunen, Liisa M.
    Kucklick, John R.
    Kylin, Henrik
    Letcher, Robert J.
    Tysklind, Mats
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Wong, Fiona
    A review of halogenated natural products in Arctic, Subarctic and Nordic ecosystems2019In: Emerging Contaminants, ISSN 2405-6650, E-ISSN 2405-6642, Vol. 5, p. 89-115Article in journal (Refereed)
    Abstract [en]

    Halogenated natural products (HNPs) are organic compounds containing bromine, chlorine, iodine, and rarely fluorine. HNPs comprise many classes of compounds, ranging in complexity from halocarbons to higher molecular weight compounds, which often contain oxygen and/or nitrogen atoms in addition to halogens. Many HNPs are biosynthesized by marine bacteria, macroalgae, phytoplankton, tunicates, corals, worms, sponges and other invertebrates. This paper reviews HNPs in Arctic, Subarctic and Nordic ecosystems and is based on sections of Chapter 2.16 in the Arctic Monitoring and Assessment Program (AMAP) assessment Chemicals of Emerging Arctic Concern (AMAP, 2017) which deal with the higher molecular weight HNPs. Material is updated and expanded to include more Nordic examples. Much of the chapter is devoted to “bromophenolic” HNPs, viz bromophenols (BPs) and transformation products bromoanisoles (BAs), hydroxylated and methoxylated bromodiphenyl ethers (OH-BDEs, MeO-BDEs) and polybrominated dibenzo-p-dioxins (PBDDs), since these HNPs are most frequently reported. Others discussed are 2,2′ -dimethoxy-3,3′ ,5,5′ -tetrabromobiphenyl (2,2′ -dimethoxy-BB80), polyhalogenated 1′- methyl-1,2′-bipyrroles (PMBPs), polyhalogenated 1,1′ -dimethyl-2,2′ -bipyrroles (PDBPs), polyhalogenated N-methylpyrroles (PMPs), polyhalogenated N-methylindoles (PMIs), bromoheptyl- and bromooctyl pyrroles, (1R,2S,4R,5R,1′E)-2-bromo-1-bromomethyl-1,4-dichloro-5-(2′-chloroethenyl)-5- methylcyclohexane (mixed halogenated compound MHC-1), polybrominated hexahydroxanthene derivatives (PBHDs) and polyhalogenated carbazoles (PHCs). Aspects of HNPs covered are physicochemical properties, sources and production, transformation processes, concentrations and trends in the physical environment and biota (marine and freshwater). Toxic properties of some HNPs and a discussion of how climate change might affect HNPs production and distribution are also included. The review concludes with a summary of research needs to better understand the role of HNPs as “chemicals of emerging Arctic concern”.

  • 379.
    Bidleman, Terry F.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Letter to the Editor regarding 'Celebrating Bidleman's 1988 "Atmospheric Processes"2015In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 49, no 5, p. 2586-2586Article in journal (Refereed)
  • 380.
    Bidleman, Terry F.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Agosta, Kathleen
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Andersson, Agneta
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Haglund, Peter
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Liljelind, Per
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Hegmans, Alyse
    Jantunen, Liisa M.
    Nygren, Olle
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Poole, Justen
    Ripszam, Matyas
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Tysklind, Mats
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Sea-air exchange of bromoanisoles and methoxylated bromodiphenylethers in the Northern Baltic2016In: Marine Pollution Bulletin, ISSN 0025-326X, E-ISSN 1879-3363, Vol. 112, no 1-2, p. 58-64Article in journal (Refereed)
    Abstract [en]

    Halogenated natural products in biota of the Baltic Sea include bromoanisoles (BAs) and methoxylated bromodiphenyl ethers (MeO-BDEs). We identified biogenic 6-MeO-BDE47 and 2'-MeO-BDE68 in Baltic water and air for the first time using gas chromatography - high resolution mass spectrometry. Partial pressures in air were related to temperature by: log p/Pa=m/T(K)+b. We determined Henry's law constants (HLCs) of 2,4-dibromoanisole (2,4-DiBA) and 2,4,6-tribromoanisole (2,4,6-TriBA) from 5 to 30°C and revised our assessment of gas exchange in the northern Baltic. The new water/air fugacity ratios (FRs) were lower, but still indicated net volatilization in May-June for 2,4-DiBA and May - September for 2,4,6-TriBA. The net flux (negative) of BAs from Bothnian Bay (38,000km2) between May - September was revised from -1319 to -532kg. FRs of MeO-BDEs were >1, suggesting volatilization, although this is tentative due to uncertainties in their HLCs and binding to dissolved organic carbon.

  • 381.
    Bidleman, Terry F.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Agosta, Kathleen
    Andersson, Agneta
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Haglund, Peter
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Nygren, Olle
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Ripszam, Matyas
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Tysklind, Mats
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Air-water exchange of brominated anisoles in the northern baltic sea2014In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 48, no 11, p. 6124-6132Article in journal (Refereed)
    Abstract [en]

    Bromophenols produced by marine algae undergo O-methylation to form bromoanisoles (BAs), which are exchanged between water and air. BAs were determined in surface water of the northern Baltic Sea (Gulf of Bothnia, consisting of Bothnian Bay and Bothnian Sea) during 2011-2013 and on a transect of the entire Baltic in September 2013. The abundance decreased in the following order: 2,4,6-tribromoanisole (2,4,6-TBA) > 2,4-dibromoanisole (2,4-DBA) ≫ 2,6-dibromoanisole (2,6-DBA). Concentrations of 2,4-DBA and 2,4,6-TBA in September were higher in the southern than in the northern Baltic and correlated well with the higher salinity in the south. This suggests south-to-north advection and dilution with fresh riverine water enroute, and/or lower production in the north. The abundance in air over the northern Baltic also decreased in the following order: 2,4,6-TBA > 2,4-DBA. However, 2,6-DBA was estimated as a lower limit due to breakthrough from polyurethane foam traps used for sampling. Water/air fugacity ratios ranged from 3.4 to 7.6 for 2,4-DBA and from 18 to 94 for 2,4,6-TBA, indicating net volatilization. Flux estimates using the two-film model suggested that volatilization removes 980-1360 kg of total BAs from Bothnian Bay (38000 km(2)) between May and September. The release of bromine from outgassing of BAs could be up to 4-6% of bromine fluxes from previously reported volatilization of bromomethanes and bromochloromethanes.

  • 382.
    Bidleman, Terry F.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Andersson, Agneta
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Umeå University, Faculty of Science and Technology, Umeå Marine Sciences Centre (UMF).
    Brugel, Sonia
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Umeå University, Faculty of Science and Technology, Umeå Marine Sciences Centre (UMF).
    Ericson, Lars
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Haglund, Peter
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Kupryianchyk, Darya
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Lau, Danny C. P.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Liljelind, Per
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Lundin, Lisa
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Tysklind, Anders
    Tysklind, Mats
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Bromoanisoles and Methoxylated Bromodiphenyl Ethers in Macroalgae from Nordic Coastal Regions2019In: Environmental Science: Processes & Impacts, ISSN 2050-7887, E-ISSN 2050-7895, p. 881-892Article in journal (Refereed)
    Abstract [en]

    Marine macroalgae are used worldwide for human consumption, animal feed, cosmetics and agriculture. In addition to beneficial nutrients, macroalgae contain halogenated natural products (HNPs), some of which have toxic properties similar to those of well-known anthropogenic contaminants. Sixteen species of red, green and brown macroalgae were collected in 2017–2018 from coastal waters of the northern Baltic Sea, Sweden Atlantic and Norway Atlantic, and analyzed for bromoanisoles (BAs) and methoxylated bromodiphenyl ethers (MeO-BDEs). Target compounds were quantified by gas chromatography-low resolution mass spectrometry (GC-LRMS), with qualitative confirmation in selected species by GC-high resolution mass spectrometry (GC-HRMS). Quantified compounds were 2,4-diBA, 2,4,6-triBA, 2′-MeO-BDE68, 6-MeO-BDE47, and two tribromo-MeO-BDEs and one tetrabromo-MeO-BDE with unknown bromine substituent positions. Semiquantitative results for pentabromo-MeO-BDEs were also obtained for a few species by GC-HRMS. Three extraction methods were compared; soaking in methanol, soaking in methanol–dichloromethane, and blending with mixed solvents. Extraction yields of BAs did not differ significantly (p > 0.05) with the three methods and the two soaking methods gave equivalent yields of MeO-BDEs. Extraction efficiencies of MeO-BDEs were significantly lower using the blend method (p < 0.05). For reasons of simplicity and efficiency, the soaking methods are preferred. Concentrations varied by orders of magnitude among species: ∑2BAs 57 to 57 700 and ∑5MeO-BDEs < 10 to 476 pg g−1 wet weight (ww). Macroalgae standing out with ∑2BAs >1000 pg g−1 ww were Ascophyllum nodosumCeramium tenuicorneCeramium virgatumFucus radicansFucus serratusFucus vesiculosusSaccharina latissimaLaminaria digitata, and Acrosiphonia/Spongomorpha sp. Species A. nodosumC. tenuicorneChara virgataF. radicans and F. vesiculosus (Sweden Atlantic only) had ∑5MeO-BDEs >100 pg g−1ww. Profiles of individual compounds showed distinct differences among species and locations.

  • 383.
    Bidleman, Terry F.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Brorström-Lundén, Eva
    Hansson, Katarina
    Laudon, Hjalmar
    Nygren, Olle
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Tysklind, Mats
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Atmospheric transport and deposition of bromoanisoles along a temperate to arctic gradient2017In: Environmental Science and Technology, ISSN 1086-931X, E-ISSN 1520-6912, Vol. 51, no 19, p. 10974-10982Article in journal (Refereed)
    Abstract [en]

    Bromoanisoles (BAs) arise from O-methylation of bromophenols, produced by marine algae and invertebrates. BAs undergo sea-air exchange and are transported over the oceans. Here we report 2,4-DiBA and 2,4,6-TriBA in air and deposition on the Swedish west coast (Råö) and the interior of arctic Finland (Pallas). Results are discussed in perspective with previous measurements in the northern Baltic region in 2011−2013. BAs in air decreased from south to north in the order Råö > northern Baltic > Pallas. Geometric mean concentrations at Pallas increased significantly (p < 0.05) between 2002 and 2015 for 2,4-DiBA but not for 2,4,6-TriBA. The logarithm of BA partial pressures correlated significantly to reciprocal air temperature at the coastal station Råö and over the Baltic, but only weakly (2,4-DiBA) or not significantly (2,4,6-TriBA) at inland Pallas. Deposition fluxes of BAs were similar at both sites despite lower air concentrations at Pallas, due to greater precipitation scavenging at lower temperatures. Proportions of the two BAs in air and deposition were related to Henry’s law partitioning and source regions. Precipitation concentrations were 10−40% of those in surface water of Bothnian Bay, northern Baltic Sea. BAs deposited in the bay catchment likely enter rivers and provide an unexpected source to northern estuaries. BAs may be precursors to higher molecular weight compounds identified by others in Swedish inland lakes.

  • 384.
    Bidleman, Terry F.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Jantunen, L. M
    Hung, H
    Ma, J
    Stern, G. A.
    Rosenberg, B
    Racine, J
    Biannual cycles of organochlorine pesticide enantiomers in arctic air suggest changing sources and pathways2014In: Atmospheric Chemistry and Physics Discussions, ISSN 1680-7367, E-ISSN 1680-7375, Vol. 14, no 17, p. 25027-25050Article in journal (Refereed)
    Abstract [en]

    Air samples collected during 1994–2000 at the Canadian arctic air monitoring stationAlert (82300 N, 62200 W) were analyzed by enantiospecific gas chromatography –mass spectrometry for -hexachlorocyclohexane (-HCH), trans-chlordane (TC) and5 cis-chlordane (CC). Results were expressed as enantiomer fractions (EF = quantitiesof (+)/[(+)+(−)] enantiomers), where EFs=0.5, < 0.5 and > 0.5 indicate racemic composition,and preferential depletion of (+) and (−) enantiomers, respectively. Long-termaverage EFs were close to racemic values for -HCH (0.504±0.004, n =197) andCC (0.505±0.004, n =162), and deviated farther from racemic for TC (0.470±0.013,10 n =165). Digital filtration analysis revealed biannual cycles of lower -HCH EFs insummer-fall and higher EFs in winter-spring. These cycles suggest volatilization ofpartially degraded -HCH with EF < 0.5 from open water and advection to Alert duringthe warm season, and background transport of -HCH with EF> 0.5 during the coldseason. The contribution of sea-volatilized -HCH was only 11% at Alert, vs. 32%15 at Resolute Bay (74.68 N, 94.90W) in 1999. EFs of TC also followed biannual cyclesof lower and higher values in the warm and cold seasons. These were in phasewith low and high cycles of the TC/CC ratio (expressed as FTC =TC/(TC+CC)), whichsuggests greater contribution of microbially “weathered” TC in summer-fall vs. winterspring.CC was closer to racemic than TC and displayed seasonal cycles only in 1997–20 1998. EF profiles are likely to change with rising contribution of secondary emissionsources, weathering of residues in the environment, and loss of ice cover in the Arctic.Enantiomer-specific analysis could provide added forensic capability to air monitoringprograms.

  • 385.
    Bidleman, Terry F
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Jantunen, Liisa M
    Kurt‐Karakus, Perihan Binnur
    Wong, Fiona
    Chiral persistent organic pollutants as tracers of atmospheric sources and fate: review and prospects for investigating climate change influences2012In: Atmospheric Pollution Research, ISSN 1309-1042, Vol. 3, no 4, p. 371-382Article in journal (Refereed)
    Abstract [en]

    Elimination of persistent organic pollutants (POPs) under national and international controls reduces “primary” emissions, but “secondary” emissions continue from residues deposited in soil, water, ice and vegetation during former years of high usage. Secondary sources are expected to dominate in the future, when POPs transport and accumulation will be controlled by air–surface exchange and the biogeochemical cycle of organic carbon. Climate change is likely to affect mobilization of POPs through, e.g., increased temperature, loss of ice cover in polar regions, melting glaciers and changes in soil and water microbiology which affect degradation and transformation. Chiral compounds offer advantages for following transport and fate pathways because of their ability to distinguish racemic (newly released or protected from microbial attack) and nonracemic (microbially altered) sources. Here we explain the rationale for this approach and suggest applications where chiral POPs could aid investigation of climate–mediated exchange and degradation processes. Examples include distinguishing agricultural vs. non–agricultural and recently used vs. residual pesticides, degradation and sequestration processes in soil, historical vs. recent atmospheric deposition, sources in arctic air and influence of ice cover on volatilization.

  • 386.
    Bidleman, Terry F.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Centre for Atmospheric Research Experiments, Environment Canada, Ontario, Canada.
    Kurt-Karakus, Perihan B.
    Department of Environmental Engineering, Faculty of Natural Sciences, Architecture and Engineering, Bursa Technical University, Turkey.
    Wong, Fiona
    Department of Applied Environmental Science (ITM), Stockholm University.
    Alegria, Henry A.
    Department of Environmental Science, Policy and Geography, University of South Florida St. Petersburg, U.S.A..
    Jantunen, Liisa M.
    Centre for Atmospheric Research Experiments, Environment Canada, Ontario, Canada.
    Hung, Hayley
    Environment Canada, Ontario, Canada.
    Is there still “new” DDT in North America?: an investigation using proportions of DDT compounds2013In: Occurrence, fate and impact of atmospheric pollutants on environmental and human health / [ed] Laura L. McConnell, Jordi Dachs, Cathleen J. Hapeman, American Chemical Society (ACS), 2013, p. 153-181Chapter in book (Refereed)
    Abstract [en]

    Usage of DDT ceased over four decades ago in Canada and the United States, and since 2000 in Mexico. Potential sources in the North American atmosphere today include emissions of legacy residues from soils and long-range transport from other countries where DDT is still used or recently banned. Distinction of source types is investigated here using proportions of p,p′-DDT, o,p′-DDT, p,p′-DDE and p,p′-DDD. The relative volatilization of DDT compounds can be accurately described by their subcooled liquid vapor pressures (PL); e.g., (p,p′-DDT/p,p′-DDE)AIR = (p,p′-DDT/p,p′-DDE)SOIL x PL, DDT/PL,DDE. Using this model, the expected proportions in air due to volatilization from technical DDT and from soils in Canada, the U.S.A. and Mexico were estimated and expressed as the fractions FDDTE = p,p′-DDT/(p,p′-DDT + p,p′-DDE), FDDTO = p,p′-DDT/(p,p′-DDT + o,p′-DDT), and FDDTD = p,p′-DDT/(p,p′-DDT + p,p′-DDD). FDDTE, FDDTO and FDDTD predicted from soil emissions were compared to compound fractions in ambient air sampled at the Integrated Atmospheric Deposition Network (IADN) of stations on the Great Lakes between Canada and the U.S.A., and at arctic monitoring stations. FDDTE in air at IADN stations on lakes Erie, Ontario, Michigan and Huron were lower than in technical DDT vapor. This is consistent with emissions of aged residues from agricultural land and urban centers near these lakes. By comparison, FDDTE values were higher at stations on Lake Superior where atmospheric DDT is likely due to long-range transport rather than regional soil emissions. FDDTE increased from the early 1990s to 2005 at the Lake Superior stations and at the Canadian arctic station Alert between 2002-2005, whereas a significant decline in FDDTE was observed at the Norwegian arctic station Zeppelin Mountain. The mean FDDTO in air at IADN stations were consistent with either soil emissions or technical DDT composition, but annual values showed significant downward trends at two Canadian stations, and also decreased with time at Zeppelin Mountain (but not at Alert). These trends might signify contribution from “dicofol-type” DDT sources, which have a lower FDDTO than technical DDT or soil emissions, or preferential degradation of p,p′-DDT vs. o,p′-DDT over time. FDDTD in air at IADN stations were lower than in technical DDT vapor, showing the influence of soil sources. The enantiomer proportions of the chiral compounds o,p′-DDT and o,p′-DDD were nonracemic in some soils and ambient air, but enantiospecific analysis has not been done for IADN air samples. It is suggested that isomer, parent/metabolite and enantiomer composition information be incorporated into air monitoring programs to help identify sources.

  • 387.
    Bidleman, Terry F.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Laudon, Hjalmar
    Nygren, Olle
    Lokalförsörjningsenheten, Umeå universitet.
    Svanberg, Staffan
    Tysklind, Mats
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Chlorinated pesticides and natural brominated anisoles in air at three northern Baltic stations2017In: Environmental Pollution, ISSN 0269-7491, E-ISSN 1873-6424, Vol. 225, p. 381-389Article in journal (Refereed)
    Abstract [en]

    Abstract Polyurethane foam (PUF) disk passive samplers were deployed at one inland and two island locations in the Bothnian Bay region of the northern Baltic Sea. Uptake was linear over 81–147 d and a temperature range of −2.6 to 14.2 °C for organochlorine pesticides (OCPs) and current-use pesticides (CUPs) having log KOA ≥9 at ambient temperatures. Partial saturation of the PUF disks occurred for the more volatile OCPs hexachlorocyclohexanes (HCHs) and hexachlorobenzene (HCB), and for bromoanisoles (BAs), which are products of bromophenols released by natural and anthropogenic sources. Correction for nonlinear uptake of these was made using experimentally measured PUF-air partition coefficients. Passive-derived air concentrations of pesticides were uniform over the bay and agreed within a factor of 2 or better with levels determined by active (pumped) sampling at one of the island stations. Levels of OCPs were similar to those reported at background sites in the European and Canadian Arctic and at monitoring stations in the central Baltic and southern Scandinavia, indicating long-range transport. The insecticide chlorpyrifos was 10 times lower at bay stations than in the Canadian Arctic. Insight to sources and processes was gained by examining compound profiles. Fractions Falpha = α-HCH/(α-HCH + γ-HCH) and FTC = trans-chlordane/(trans-chlordane + cis-chlordane) at bay stations were higher than in the Norwegian and Finnish Arctic and similar to those at the southern monitoring stations. Volatilization of chlordanes from Baltic seawater may also modify FTC. Higher FTriBA = 2,4,6-TriBA/(2,4,6-TriBA + 2,4-DiBA) distinguished local volatilization from the Baltic Sea versus lower FTriBA found at the inland site and reported in air on the Norwegian coast, suggesting westerly transport from the Atlantic across Norway and Sweden.

  • 388. Bidleman, Terry F
    et al.
    Leone, Andi D
    Falconer, Renee L
    Harner, Tom
    Jantunen, Liisa M M
    Wiberg, Karin
    Umeå University, Faculty of Science and Technology, Chemistry.
    Helm, Paul A
    Diamond, Miriam L
    Loo, Binh
    Chiral Pesticides in Soil and Water and Exchange with the Atmosphere2002In: TheScientificWorldJOURNAL, Vol. 2, p. 357-373Article in journal (Refereed)
    Abstract [en]

    The enantiomers of chiral pesticides are often metabolised at different rates in soil and water, leading to nonracemic residues. This paper reviews enantioselective metabolism of organochlorine pesticides (OCPs) in soil and water, and the use of enantiomers to follow transport and fate processes. Residues of chiral OCPs and their metabolites are frequently nonracemic in soil, although exceptions occur in which the OCPs are racemic. In soils where enantioselective degradation and/or metabolite formation has taken place, some OCPs usually show the same degradation preference — e.g., depletion of (+)trans-chlordane (TC) and (-)cis-chlordane (CC), and enrichment of the metabolite (+)heptachlor exo-epoxide (HEPX). The selectivity is ambivalent for other chemicals; preferential loss of either (+) or (-)o,p?-DDT and enrichment of either (+) or (-)oxychlordane (OXY) occurs in different soils. Nonracemic OCPs are found in air samples collected above soil which contains nonracemic residues. The enantiomer profiles of chlordanes in ambient air suggests that most chlordane in northern Alabama air comes from racemic sources (e.g., termiticide emissions), whereas a mixture of racemic and nonracemic (volatilisation from soil) sources supplies chlordane to air in the Great Lakes region. Chlordanes and HEPX are also nonracemic in arctic air, probably the result of soil emissions from lower latitudes. The (+) enantiomer of a-hexachlorocyclohexane (a-HCH) is preferentially metabolised in the Arctic Ocean, arctic lakes and watersheds, the North American Great Lakes, and the Baltic Sea. In some marine regions (the Bering and Chukchi Seas, parts of the North Sea) the preference is reversed and (-)a-HCH is depleted. Volatilisation from seas and large lakes can be traced by the appearance of nonracemic a-HCH in the air boundary layer above the water. Estimates of microbial degradation rates for a-HCH in the eastern Arctic Ocean and an arctic lake have been made from the enantiomer fractions (EFs) and mass balance in the water column. Apparent pseudo first-order rate constants in the eastern Arctic Ocean are 0.12 year-1 for (+)a-HCH, 0.030 year-1 for (-)a-HCH, and 0.037 year-1 for achiral ?-HCH. These rate constants are 3–10 times greater than those for basic hydrolysis in seawater. Microbial breakdown may compete with advective outflow for long-term removal of HCHs from the Arctic Ocean. Rate constants estimated for the arctic lake are about 3–8 times greater than those in the ocean.

  • 389.
    Bidleman, Terry F.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Melymuk, Lisa
    Forty-five years of foam: a retrospective on air sampling with polyurethane foam2019In: Bulletin of Environmental Contamination and Toxicology, ISSN 0007-4861, E-ISSN 1432-0800, Vol. 102, no 4, p. 447-449Article in journal (Refereed)
  • 390.
    Bidleman, Terry F.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Nygren, Olle
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Tysklind, Mats
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Field estimates of polyurethane foam: air partition coefficients for hexachlorobenzene, alpha-hexachlorocyclohexane and bromoanisoles2016In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 159, p. 126-131Article in journal (Refereed)
    Abstract [en]

    Partition coefficients of gaseous semivolatile organic compounds (SVOCs) between polyurethane foam (PUF) and air (KPA) are needed in the estimation of sampling rates for PUF disk passive air samplers. We determined KPA in field experiments by conducting long-term (24-48 h) air sampling to saturate PUF traps and shorter runs (2-4 h) to measure air concentrations. Sampling events were done at daily mean temperatures ranging from 1.9 to 17.5 °C. Target compounds were hexachlorobenzene (HCB), alpha-hexachlorocyclohexane (α-HCH), 2,4-dibromoanisole (2,4-DiBA) and 2,4,6-tribromoanisole (2,4,6-TriBA). KPA (mL g(-1)) was calculated from quantities on the PUF traps at saturation (ng g(-1)) divided by air concentrations (ng mL(-1)). Enthalpies of PUF-to-air transfer (ΔHPA, kJ mol(-1)) were determined from the slopes of log KPA/mL g(-1) versus 1/T(K) for HCB and the bromoanisoles, KPA of α-HCH was measured only at 14.3 to 17.5 °C and ΔHPA was not determined. Experimental log KPA/mL g(-1) at 15 °C were HCB = 7.37; α-HCH = 8.08; 2,4-DiBA = 7.26 and 2,4,6-TriBA = 7.26. Experimental log KPA/mL g(-1) were compared with predictions based on an octanol-air partition coefficient (log KOA) model (Shoeib and Harner, 2002a) and a polyparameter linear free relationship (pp-LFER) model (Kamprad and Goss, 2007) using different sets of solute parameters. Predicted KP values varied by factors of 3 to over 30, depending on the compound and the model. Such discrepancies provide incentive for experimental measurements of KPA for other SVOCs.

  • 391.
    Bidleman, Terry F.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Tysklind, Mats
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Breakthrough during air sampling with polyurethane foam: What do PUF 2/PUF 1 ratios mean?2018In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 192, p. 267-271Article in journal (Refereed)
    Abstract [en]

    Frontal chromatography theory is applied to describe movement of gaseous semivolatile organic compounds (SVOCs) through a column of polyurethane foam (PUF). Collected mass fractions (FC) are predicted for sample volume/breakthrough volume ratios (τ = VS/VB) up to 6.0 and PUF bed theoretical plate numbers (N) from 2 to 16. The predictions assume constant air concentrations and temperatures. Extension of the calculations is done to relate the collection efficiency of a 2-PUF train (FC1+2) to the PUF 2/PUF 1 ratio. FC1+2 exceeds 0.9 for PUF 2/PUF 1 ≤ 0.5 and lengths of PUF commonly used in air samplers. As the PUF 2/PUF 1 ratio approaches unity, confidence in these predictions is limited by the analytical ability to distinguish residues on the two PUFs. Field data should not be arbitrarily discarded because some analytes broke through to the backup PUF trap. The fractional collection efficiencies can be used to estimate air concentrations from quantities retained on the PUF trap when sampling is not quantitative.

  • 392.
    Bidleman, Terry Frank
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Air Quality Processes Research Section, Environment Canada.
    Jantunen, L. M.
    Hung, H.
    Ma, J.
    Stern, G. A.
    Rosenberg, B.
    Racine, J.
    Annual cycles of organochlorine pesticide enantiomers in Arctic air suggest changing sources and pathways2015In: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 15, no 3, p. 1411-1420Article in journal (Refereed)
    Abstract [en]

    Air samples collected during 1994-2000 at the Canadian Arctic air monitoring station Alert (82 degrees 30'N, 62 degrees 20'W) were analysed by enantiospecific gas chromatography-mass spectrometry for alpha-hexachlorocyclohexane (alpha-HCH), trans-chlordane (TC) and cis-chlordane (CC). Results were expressed as enantiomer fractions (EF = peak areas of (+)/[(+) + (-)] enantiomers), where EFs = 0.5, <0.5 and >0.5 indicate racemic composition, and preferential depletion of (+) and (-) enantiomers, respectively. Long-term average EFs were close to racemic values for alpha-HCH (0.504 +/- 0.004, n = 197) and CC (0.505 +/- 0.004, n = 162), and deviated farther from racemic for TC (0.470 +/- 0.013, n = 165). Digital filtration analysis revealed annual cycles of lower alpha-HCH EFs in summer-fall and higher EFs in winter-spring. These cycles suggest volatilization of partially degraded alpha-HCH with EF < 0.5 from open water and advection to Alert during the warm season, and background transport of alpha-HCH with EF > 0.5 during the cold season. The contribution of sea-volatilized alpha-HCH was only 11% at Alert, vs. 32% at Resolute Bay (74.68 degrees N, 94.90 degrees W) in 1999. EFs of TC also followed annual cycles of lower and higher values in the warm and cold seasons. These were in phase with low and high cycles of the TC / CC ratio (expressed as F-TC = TC/(TC + CC)), which suggests greater contribution of microbially "weathered" TC in summer-fall versus winter-spring. CC was closer to racemic than TC and displayed seasonal cycles only in 1997-1998. EF profiles are likely to change with rising contribution of secondary emission sources, weathering of residues in the environment, and loss of ice cover in the Arctic. Enantiomer-specific analysis could provide added forensic capability to air monitoring programs.

  • 393.
    Bidleman, Terry Frank
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Centre for Atmospheric Research Experiments, Environment Canada, Canada.
    Jantunen, Liisa M.
    Binnur Kurt-Karakus, Perihan
    Wong, Fiona
    Hung, Hayley
    Ma, Jianmin
    Stern, Gary
    Rosenberg, Bruno
    Chiral Chemicals as Tracers of Atmospheric Sources and Fate Processes in a World of Changing Climate2013In: Mass Spectrometry, ISSN 2186-5116, Vol. 2, no 19, Special Issue: Proceedings of 19th International Mass Spectrometry Conference, p. S0019-Article in journal (Refereed)
    Abstract [en]

    Elimination of persistent organic pollutants (POPs) under national and international regulations reduces “primary” emissions, but “secondary” emissions continue from residues deposited in soil, water, ice and vegetation during former years of usage. In a future, secondary source controlled world, POPs will follow the carbon cycle and biogeochemical processes will determine their transport, accumulation and fate. Climate change is likely to affect mobilisation of POPs through e.g., increased temperature, altered precipitation and wind patterns, flooding, loss of ice cover in polar regions, melting glaciers, and changes in soil and water microbiology which affect degradation and transformation. Chiral compounds offer advantages for following transport and fate pathways because of their ability to distinguish racemic (newly released or protected from microbial attack) and nonracemic (microbially degraded) sources. This paper discusses the rationale for this approach and suggests applications where chiral POPs could aid investigation of climate-mediated exchange and degradation processes. Multiyear measurements of two chiral POPs, trans-chlordane and α-HCH, at a Canadian Arctic air monitoring station show enantiomer compositions which cycle seasonally, suggesting varying source contributions which may be under climatic control. Large-scale shifts in the enantioselective metabolism of chiral POPs in soil and water might influence the enantiomer composition of atmospheric residues, and it would be advantageous to include enantiospecific analysis in POPs monitoring programs.

  • 394.
    Bidleman, Terry Frank
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Centre for Atmospheric Research Experiments (CARE), Environment Canada, 6248 Eighth Line, Egbert, ON, L0L 1N0, Canada.
    Stern, Gary A.
    Tomy, Gregg T.
    Hargrave, Barry T.
    Jantunen, Liisa M.
    Macdonald, Robie W.
    Scavenging amphipods: sentinels for penetration of mercury and persistent organic chemicals into food webs of the deep arctic ocean2013In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 47, no 11, p. 5553-5561Article in journal (Refereed)
    Abstract [en]

    Archived specimens of the scavenging amphipod Eurythenes gryllus, collected from 2075 to 4250 m below the surface on five expeditions to the western and central Arctic Ocean between 1983 and 1998, were analyzed for total mercury (∑Hg), methyl mercury (MeHg), polychlorinated biphenyls (PCBs) and other industrial or byproduct organochlorines (chlorobenzenes, pentachloroanisole, octachlorostyrene), organochlorine pesticides (OCPs), and polybrominated diphenyl ethers (PBDEs). Median ∑Hg concentrations ranged from 70 to 366 ng g(-1) wet weight (ww). MeHg concentrations (3.55 to 23.5 ng g(-1) ww) accounted for 1.7 to 20.1% (median 3.7%) of ∑Hg. ∑Hg and MeHg were positively and significantly correlated with ww (∑Hg r(2) = 0.18, p = 0.0004, n = 63; MeHg r(2) = 0.42, p = 0.0004, n = 25), but not significantly with δ(13)C nor δ(15)N. Median concentrations of total persistent organic pollutants (POPs) ranged from 9750 to 156 000 ng g(-1) lipid weight, with order of abundance: ∑TOX (chlorobornanes quantified as technical toxaphene) > ∑PCBs > ∑DDTs > ∑chlordanes > ∑mirex compounds > ∑BDEs ∼ ∑chlorobenzenes ∼ octachlorostyrene > α-hexachlorocyclohexane ∼ hexachlorobenzene ∼ pentachloroanisole. Enantioselective accumulation was found for the chiral OCPs o,p'-DDT, cis- and trans-chlordane, nonachlor MC6 and oxychlordane. Lipid-normalized POPs concentrations were elevated in amphipods with lipid percentages ≤10%, suggesting that utilization of lipids resulted in concentration of POPs in the remaining lipid pool. Multidimensional Scaling (MDS) analysis using log-transformed physiological variables and lipid-normalized organochlorine concentrations distinguished amphipods from the central vs western arctic stations. This distinction was also seen for PCB homologues, whereas profiles of other compound classes were more related to specific stations rather than central-west differences.

  • 395. Bidleman, TF
    et al.
    Jantunen, LMM
    Harner, T
    Wiberg, K
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Wideman, JL
    Brice, K
    Su, K
    Falconer, RL
    Aigner, EJ
    Leone, AD
    Ridal, JJ
    Kerman, B
    Finizio, A
    Alegria, H
    Parkhurst, WJ
    Szeto, SY
    Chiral pesticides as tracers of air-surface exchange1998In: Environmental Pollution, ISSN 0269-7491, E-ISSN 1873-6424, Vol. 102, no 1, p. 43-49Article in journal (Refereed)
    Abstract [en]

    The enantiomers of chiral pesticides are selectively broken down in soil and water to yield residues and metabolites, which are non-racemic. The distinctive enantiomer signatures of residues are preserved upon volatilization, providing site-specific tracers for air-soil and air-water exchange. Applications of enantiomeric tracers include distinguishing the atmospheric transport of freshly applied pesticides from those which are 'recycled' from lakes, oceans and soil, and investigating biotic vs abiotic degradation pathways. Examples are given of using pesticide enantiomers to follow volatilization from the Great Lakes and arctic waters and as indicators of pesticide emissions from agricultural soils.

  • 396. Bidleman, TF
    et al.
    Jantunen, LMM
    Wiberg, Karin
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Harner, T
    Brice, K
    Su, K
    Falconer, RL
    Leone, AD
    Aigner, EJ
    Parkhurst, WJ
    Soil as a source of atmospheric heptachlor epoxide1998In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 32, no 10, p. 1546-1548Article in journal (Refereed)
    Abstract [en]

    The chiral pesticide heptachlor can undergo photolysis to yield the racemic products heptachlor-exo-epoxide (HEPX) and photoheptachlor. Heptachlor is also metabolized to nonracemic HEPX in biological systems and soils. HEPX in ambient air samples from the southern United States and Lakes Ontario and Superior was nonracemic and enriched in the (+) enantiomer. Average enantiomer ratios (ER = areas of (+)/(-) HEPX) in these locations ranged from 1.51 to 2.02, and were similar to ER values of HEPX reported for agricultural soils. Airborne heptachlor was racemic, with ERs of 0.98-1.02. These results suggest that the main source of HEPX in ambient air is not photolysis of heptachlor, hut rather metabolism of heptachlor in soils followed by volatilization of HEPX. The study exemplifies the use of chiral analysis for investigating the environmental fate of pesticides.

  • 397. Bidleman, TF
    et al.
    Leone, AD
    Falconer, RL
    Harner, T
    Jantunen, LM
    Wiberg, Karin
    Umeå University, Faculty of Science and Technology, Chemistry.
    Helm, PA
    Diamond, ML
    Loo, B
    Air-soil and air-water exchange of chiral pesticides2003In: ENVIRONMENTAL FATE AND EFFECTS OF PESTICIDES Book Series: ACS SYMPOSIUM SERIES, ISSN 0097-6156, Vol. 853, p. 196-225Article in journal (Refereed)
    Abstract [en]

    The enantiomers of chiral pesticides are often metabolized at different rates in soil and water, leading to non-racemic residues. This paper reviews enantioselective metabolism of organochlorine pesticides (OCPs) in soil and water, and the use of enantiomers to follow transport and fate processes. Residues of chiral OCPs and their metabolites are frequently non-racemic in soil, although exceptions occur in which the OCPs are racemic. In soils where enantioselective degradation and/or metabolite formation has taken place, some OCPs usually show the same degradation preference; e.g. depletion of (+)trans-chlordane (TC) and (-)cis-chlordane (TC), and enrichment of the metabolite (+)heptachlor exo-epoxide (HEPX). The selectivity is ambivalent for other chemicals; preferential loss of either (+) or (-)o,p'-DDT and enrichment of either (+) or (-)oxychlordane (OXY) occurs in different soils.

    Non-racemic OCPs are found in air samples collected above soil which contains non-racemic residues. The enantiomer profiles of chlordanes in ambient air suggests that most chlordane in northern Alabama air comes from racemic sources (e.g. termiticide emissions), whereas a mixture of racemic and non-racemic (volatilization from soil) sources supplies chlordane to air in the Great Lakes region. Chlordanes and heptachlor exo-epoxide (HEPX) are also non-racemic in arctic air, probably the result of soil emissions from lower latitudes.

    The (+) enantiomer of alpha-hexachlorocyclohexane (alpha-HCH) is preferentially metabolized in the Arctic Ocean, arctic lakes and watersheds, the North American Great Lakes and the Baltic Sea. In some marine regions (Bering and Chukchi seas, parts of the North Sea) the preference is reversed and (-)alpha-HCH is depleted. Volatilization from seas and large lakes can be traced by the appearance of non-racemic alpha-HCH in the air boundary layer above the water. Estimates of microbial degradation rates for alpha-HCH in the eastern Arctic Ocean and an arctic lake have been made from the enantiomer fractions (EFs) and mass balance in the water column. Apparent pseudo first-order rate constants in the eastern Arctic Ocean are 0.12 y(-1) for (+)alpha-HCH 0.030 y(-1) for (-)alpha-HCH, and 0.037 y(-1) for achiral gamma-HCH. These rate constants are 3-10 times greater than those for basic hydrolysis in seawater. Microbial breakdown may compete with advective outflow for long-term removal of HCHs from the Arctic Ocean. Rate constants estimated for the arctic lake are about 3-8 times greater than those in the ocean.

  • 398. Bidleman, TF
    et al.
    Leone, AD
    Falconer, RL
    Harner, T
    Jantunen, LM
    Wiberg, Karin
    Umeå University, Faculty of Science and Technology, Chemistry.
    Helm, PA,
    Diamond, ML
    Loo, B
    Air-soil and air-water exchange of chiral pesticides2002In: Environmental Fate and Effects of Pesticides, American Chemical Soicety, Washington , 2002Chapter in book (Other academic)
  • 399. Bielig, H
    et al.
    Rompikuntal, Pramod Kumar
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Mitesh, Dongre
    Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine).
    Zurek, B
    Lindmark, B
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Ramstedt, Madeleine
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Wai, Sun Nyunt
    Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine).
    Kufer, T A
    University of Cologne.
    NOD-like receptor activation by outer-membrane vesicles (OMVs) from non-O1 non-O139 Vibrio cholerae is modulated by the quorum sensing regulator HapR2011In: Infection and Immunity, ISSN 0019-9567, E-ISSN 1098-5522, Vol. 79, no 4, p. 1418-1427Article in journal (Refereed)
    Abstract [en]

    Vibrio cholerae is an inhabitant of aquatic systems and one of the causative agents of severe dehydrating diarrhea in humans. It has also emerged as an important cause of different kinds of inflammatory responses and in particular, V. cholerae strains of the non-O1 non-O139 serogroups (NOVC) have been associated with such infections in human. We analyzed the potential of outer membrane vesicles (OMVs) derived from the NOVC strain V:5/04 to induce inflammatory responses in human host cells. V:5/04 OMVs were taken up by human epithelial cells and induced inflammatory responses. siRNA-mediated gene knock-down revealed that the inflammatory potential of NOVC OMVs was partially mediated by the nucleotide-binding domain, leucine rich repeat containing family member NOD1. Physiochemical analysis of the content of these OMVs, in conjunction with NOD1 and NOD2 reporter assays in HEK293T cells, confirmed the presence of both NOD1 and NOD2 active peptidoglycan in the OMVs. Furthermore, we show that deletion of the quorum sensing regulator HapR which mimics an infective life style, specifically reduced the inflammatory potential of the V:5/04 OMVs and their ability to activate NOD1 and NOD2. In conclusion, our study shows that NOVC OMVs elicit immune responses mediated by NOD1 and NOD2 in mammalian host cells. Moreover, we provide evidence that the quorum sensing machinery plays an important regulatory role in this process by attenuating the inflammatory potential of OMVs in infective conditions. This work thus identified a new facet of how Vibrio affects host immune responses and defines a role for the quorum sensing machinery in this process.

  • 400.
    Bignert, Anders
    et al.
    Contaminant Research Group, Swedish Museum of Natural History, Stockholm, Sweden.
    Nyberg, Elisabeth
    Contaminant Research Group, Swedish Museum of Natural History, Stockholm, Sweden.
    Sundqvist, Kristina
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Wiberg, Karin
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Spatial variation in concentrations and patterns of the PCDD/F and dioxin-like-PCB content in herring from the northern Baltic Sea2007In: Journal of Environmental Monitoring, ISSN 1464-0325, E-ISSN 1464-0333, Vol. 9, no 6, p. 550-556Article in journal (Refereed)
    Abstract [en]

    The purpose of the current study was to investigate spatial and seasonal variation of dioxin and dioxin-like PCB (dl-PCB) content in herring sampled along the northern Baltic Sea coast and map out risk zones for dioxins and dl-PCBs. We further aimed to investigate relationships between congener distribution (pattern) and sampling location and season. The results showed that there were distinct geographical differences in concentrations of dioxins, dibenzofurans and dl-PCBs along the Swedish coast, from the Bothnian Bay to north Baltic Proper, with the highest levels detected in the southern Bothnian Sea. The majority of the locations showed concentrations above the prescribed maximum for dioxin residues (4 TEQ pg g–1 wet weight [w.w.]). If all the edible parts of the fish (muscle, subcutaneous fat and skin) are considered, the estimated concentrations exceeded the prescribed maximum level in the whole study area for herring collected during spring–summer. Concentrations in herring caught during spring–summer compared to concentrations in herring sampled in the autumn indicated seasonal variation. The pattern analysis showed a variation in relative congener concentration at the different sampling locations (spring–summer). Pattern differences were also noticed between seasons.

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